This invention relates to new and useful improvements in governors for vehicle engines and more particularly is concerned with means to limit powered RPM's in pressure time vehicle engine fuel systems.
Various types of governors have been employed to control upper speed limits of vehicles for safety, for fuel economy, for protection of mechanical portions of the vehicle, for complying with governmental or management regulations, and for other reasons. Some devices heretofore used shut down the power by stopping the fuel flow when a selected vehicle or engine speed is reached. This type of system has the disadvantage of providing only "on and off" control over the power means. Such has been found to be detrimental to the drive train of the vehicle and also makes driving difficult. That is, an on-off control causes a sudden, stressful reaction, or backlash, on the drive elements of the vehicle and such causes damage to the mechanism as well as reducing driver control, especially under slippery road conditions. Other governors utilize mechanisms which adjust fuel flow according to the speed of the vehicle. Such speed control may result in compliance with required conditions, but here again there may be backlash and reduction of driver control. Driver control of a vehicle is very important, particularly for trucks. Many prior devices also have the disadvantage of being complicated and thus expensive.